These Active Noise Cancelling Headphones blockout ambient background noise. They improve concentration of listening without the annoyance of fan noise from computers or engine noise. Adjustable headband and soft earpads ensures a comfortable fit. On/off switch with LED to indicate when noise cancelling active. Powered by AAA battery, the noise cancelling can be switched off if not required. Both models include carry pouch, dual plug adaptor compatible with aircraft sound systems and one AAA battery.